I hope you know that's a terrible idea.
If you want people to follow your channel you shouldn't make them feel bad. People will follow your channel if it makes them feel good. A video asking for subscribers is basically a video asking for no subscribers.
I don't even do youtube but that is horrifically obvious to me
Well, I say "feel bad" it's not like a guilt trip or anything. It's more humorous.
I am Buzz Lightyear in the scene where he finds out he's a toy. He looks at his wrist, seeing he only has 41 subscribers (Jacksepticeye has 16M+) I look at a window where Jacksepticeye is. I decide to try and reach his level (yelling "To Jacksepticeye and beyond") I jump, fall and hit reality (the stairs) and my arm comes off from trying too hard. Then a caption so up asking you to subscribe.
Besides, no one will see it! No one comments (subscribed or otherwise) and if they do, they won't subscribe! That's how YouTube works! No one just subscribes to you just to be nice!
I don't even know how/why I have 45 subs. No one comments or anything! And if someone does, it's someone who isn't subscribed. Usually get links instagram profiles.
But yes. I know it's bad.